Prof David Porter discusses a trial looking at the use of genetically modified (GM) T-lymphocytes from a patient’s own body to target leukaemia cancer cells. Following promising laboratory results this technique was applied in the patient setting to treat advanced chronic lymphocytic leukaemia (CLL). Although the approach has only used in a small number of patients, the results have been dramatic. The modification of t-cells in this way is not a new concept but previous attempts have failed because the GM cells did not survive for long in the patient’s body. This trial has seemingly overcome this issue and in some cases GM cells have survived for over a year. These cells which remain in the patient’s body act as a vaccine and will attack any subsequent growth of tumour cells. Prof Porter explains that patients do experience a consistent level of adverse effects, but that managing these was relatively straightforward.